filtered water enters a 4-inch inner diameter perforated Schedule 40 PVC
Underdrain Pipe placed within 8 inches of gravel at the base of the chamber.
Treated water is conveyed within the pipe to the adjacent Outlet Chamber
positioned directly underneath the Trash Shelf.
Step 4. Outlet Chamber
Both the water quality treatment flow from the Biofiltration Chamber and any
associated bypass flow is routed into the Outlet Chamber prior to discharge. The
outlet pipe can be placed on either of the two sides of the chamber to facilitate
installation designs.
Step 5. Internal Bypass Weir
The standard Bio-Filter
TM
design includes an Internal Bypass designed not only to
accommodate high flow conditions, but also to minimize the device’s installation
footprint by eliminating the need for any external bypass structures. Internal
bypass occurs when the head level rises within the unit such that flows in excess
of the water quality treatment flow will spill across the overflow weir on the
Trash Shelf and downward into the underlying Outlet Chamber. The bypass weir
is screened to prevent escape of trash and debris during high-flow events.
Bio-Filter
TM
Biomedia
The natural proprietary engineered biomedia used in the Bio-Filter
TM
system is
capable of removing waterborne pollutants such as fine silts and clays, oil and
heavy metals bound to particulate matter (copper, lead, zinc) and phosphorus.
The media is configured within the Biofiltration Chamber from top to bottom as
follows:
Three (3) inches of mulch,
18 to 24 inches of a proprietary blend of natural biomedia having an
infiltration capacity between 120 and 135 inches per hour.
8 inches of gravel containing a 4 inch inner diameter Schedule 40 PVC
underdrain pipe perforated on the underside.
